Please look in the article from the series, that confirm 25 cars...
No GP34 by GEMO Motorsport
No Race Perfomance
Las Moras Racing and Equipe Verschuur will be different Teams.
Sellite Racing Team come with the Maserati.
Ekris Motorsport will come with the M4...http://gt4series.com/gt4-european-se...0%a8%e2%80%a8/

The series write:
"The series is set for an influx of new teams this season, with RN Vision STS (Porsche Cayman), Sean Walkinshaw Racing (Nissan 370Z) and Bullitt Racing (McLaren 570S) already confirming their entries. More familiar names like Allied Racing, Ekris Motorsport, Scuderia Villorba, Sofia Car Motorsport, Las Moras Racing and Equipe Verschuur will also be back this season, while Academy Motorsport and Sellite Racing Team will return following their series debut in 2016. "
For me, they are two different Teams.